71 lemans overheating

[Ogredaddy]

Good afternoon,
I am having issues with my car running hot when in parades and at highway speeds. If I drive normally at 55mph and not 70mph the car runs at 185 to 190 degrees. I have checked the gap between the water pump and the seperator plate and only recently noticed that in stock configuration, the 350 motor runs a 4 blade fixed fan and a 2 core radiator.
I have access to a 4 core and I have since installed a 5 blade flex fan. Will the 4 core be enough to resolve this issue or should i look into changing the water pump pulley from an 8" to a 6.5"?

 

[melsg5]

A stock setup uses a thermostatic fan clutch with a fixed blade fan with 7 blades assuming AC car.

 

[cammerjeff]

Also is the radiator shroud in good shape? Also how much advance are you running?

 

[spectrumad]

I have the same car and had a similar problem a few years ago. I have a good shroud, 7 blade clutch fan and close to stock engine. I installed a 195 thermostat, FlowKooler water pump, ColdCase radiator, put a new spring in the lower radiator hose and ensured the backplate in the water pump is gapped correctly. The only time it even approaches 200 is if I push it hard, then it barely gets there.

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[avell007]

Heavy duty clutch fan , 160 degree tstat, that 4 row rad you will be good , make sure you have a overflow can.